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There are some pitfalls in using the rate of descent method to ensure that an aircraft is level by a specific time. It does not make the method right or wrong, as we can use many different methods of ATC to achieve the final aim. But those with experience will take them in to account when formulating their plan.
Firstly, as explained by our pilot brethren, the rate is not achieved instantaneously. The autopilot system (and presumably the hand flyers as well !!) will be looking to manouevre the aircraft gently in a constant 1G manner. It may take the first 1000' of climb/descent to get everything in the right ball park.
Secondly, the rate will also start to bleed off well before the cleared level to ensure another gentle transition to level flight. You cannot expect someone to maintain a rate of 2500fpm or greater through FL270 for FL260 as per the example you give. The pilot will need to start reducing to around 500-1000 fpm at least 1500' before the cleared level. Possibly even before that depending on the aircraft type and its handling or automation characteristics.
Remember also that the advice given in RVSM airspace is to also aim for a maximum rate of 500-1000 fpm between 1500' and 1000' before the cleared level. Otherwise (as per the thread in ATC Forum which is talking about TCAS), you are very likely to get RAs starting to muck up your day.
I'd agree with the fact that UK controllers tend not to use this method very much. Our preference seems to be more geared to specifying levels required at positions and then letting the pilot work it all out (or Honeywell or Sextant). Just the way we've been brought up to do it I suppose.